I have updated to KDE 4.10.0 and compiled qt-core-4.8.4-r2 with -Os. Plasma-workspace is rebuild, but I can't see any running programs like kontact or dolphin in the systray. Other like console or firefox are seen in the systray. Any hints?

I have the same problem, maybe with sightly different programs (for me chromium, konsole and dolphin aren't showing).

Atm I found temporary workaround (very temporary), if You go to system settings, desktop effects, advanced and switch qt graphics system to opposite, then refresh this change triggers, will fix task manager for a while (until You log off).

You don't need to wait that long. For a start, download that patch and place it into

Code:

mkdir -p /etc/portage/patches/kde-base/kwin-4.10.1

It is required to be named `<somename>.patch`. Re-emerge kwin and watch for the patch to be applied right at the beginning._________________backend.cpp:92:2: warning: #warning TODO - this error message is about as useful as a cooling unit in the arctic